ABSTRACT
Interestingly, in a recent experimental study on all four great ape species, gorillas used visual gestures preferentially to beg for food when they were facing a human experimenter as opposed to auditory and tactile gestures. There were no significant differences between the use of auditory versus visual gestures and between auditory versus tactile gestures. In addition, the authors differentiated among tactile gestures that were not differentiated by Tanner and Byrne but that were described by them as one gesture type; tactile-close gestures. Interestingly, Redshaw and Locke, who investigated the development of behavior in two hand-reared lowland gorilla infants living together without any other conspecifics, reported auditory gestures such as chest beat, clap, and slap. In addition, tactile gestures represented the most flexible gestures, showing the highest variety of functional categories, whereas auditory and visual gestures were linked to special social contexts such as play, agonistic, and food.
